Prodigy's "Smack my Bitch up" is the best video in existence. No video will ever top it.
That said, I don't really watch MTV anymore because... well, it sucks. But recently I found myself all fucked up on a number of substances and watching MTV at some Godforsaken hour like 5am. I saw that new Britney video, and was not at all prepared for it. They really should put a warning label on things like that for those of us that have been partying a little too hard all night...